Observation of slip flow in thermophoresis

Phys Rev Lett. 2008 Oct 17;101(16):168301. doi: 10.1103/PhysRevLett.101.168301. Epub 2008 Oct 13.

Abstract

Two differing theories aim to describe fluidic thermophoresis, the movement of particles along a temperature gradient. While thermodynamic approaches rely on local equilibrium, hydrodynamic descriptions assume a quasi-slip-flow boundary condition at the particle's surface. Evidence for slip flow is presented for the case of thermal gradients exceeding (aS_(T)(-1) with particle radius a and Soret coefficient S_(T). Thermophoretic slip flow at spheres near a surface attracts or repels tracer particles perpendicular to the thermal gradient. Moreover, particles mutually attract and form colloidal crystals. Fluid dynamic slip explains the latter quantitatively.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • Crystallization
  • DNA / chemistry
  • Electrochemistry
  • Finite Element Analysis
  • Nanoparticles*
  • Particle Size
  • Polystyrenes / chemistry
  • Temperature
  • Thermodynamics

Substances

  • Polystyrenes
  • DNA